This invention relates to a structure of a switch of an electronic device like, for example, individual call signal receiver and more particularly to a structure of a switch of an electronic device of high-density parts mounting.
Conventional switches used in electronic devices often use a structure like seen in tact switches, in which a switch designed to be turned on by being pushed down is to be pushed by a push button provided upward.
FIG. 1 shows a schematic view showing an example of a conventional electronic device switch structure. This kind of conventional switch has been disclosed in for example Japanese Unexamined Patent Publication (JP-A) No. 29449 of 1955.
A push button 11 comprises an arm portion 11a, a push button portion 11b, and a switch pushing convex portion 11c. A proximal portion of the arm portion 11a elastically deformable is fixed to a case 12. The push button portion 11b is disposed on a top face of an end portion of the arm portion 11a and the switch pushing convex portion 11c is provided on a bottom thereof. A tact switch 13 is provided downward of the switch pushing convex portion 11c.
When the push button portion 11b is pushed, the arm portion 11a is elastically deformed, so that the switch pushing convex portion 11c comes into contact with the tact switch 13. If the arm portion 11a is further elastically deformed, the tact switch 13 is pushed by the switch pushing convex portion 11c so that this switch is turned on.
When a force pushing the push button portion 11b is released, the arm portion 11a elastically deformed is returned to its original position. As a result, the switch pushing convex portion 11c leaves the tact switch 13 so that the tact switch 13 is turned off.
If this kind of switch structure is applied to an individual call signal receiver, for example, a substrate and the like are arranged below an indication panel, and therefore in many cases, a battery is contained downward of the push button portion 11b.
In the individual call signal receiver in which a battery is contained downward of the push button portion 11b as described above, if it is intended to reduce the thickness of the case 12, a strong force is required for an operation of the push button portion 11b.
This reason is that in the individual call signal receiver having such a structure, if the thickness of the case 12 is reduced, the conventional switch structure shown in FIG. 1 is applied, so that the switch portion is arranged beside of the battery. At this time, there is no sufficient gap in the horizontal and vertical directions, so that the length of the arm portion 11a cannot be obtained sufficiently. Thus, when the push button portion 11b is pushed down, the arm portion 11a indicates a behavior like a rigid structure, so that the motion of the push button portion 11b requires a strong force.
On the contrary, if it is intended to weaken a force required for the operation of the push button portion 11b, in the individual call signal receiver in which a battery is contained downward of the push button portion 11b, there is no way but locating a switch between the push button portion 11b and the battery. Thus, the thickness of the case 12 must be increased.
As a switch capable of satisfying these two contradictory requirements, for example a key board switch has been known. However, this kind of switch costs too much.